Nonalcoholic Fatty Liver Disease in Pediatrics

Non-alcoholic fatty liver disease in obese children and adolescents: a role for nutrition?

Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in children, paralleling the increasing prevalence of obesity worldwide. The pathogenesis of paediatric NAFLD is not fully understood, but it is known that obesity, nutrition, lifestyle variables, genetic and epigenetic factors may be causally involved in the development of this common metabolic liver disease. In particular, obesity and nutrition are among the strongest risk factors for paediatric NAFLD, which may exert their adverse hepatic effects already before birth. Excess energy intake induces hypertrophy and hyperplasia of adipose tissue with subsequent development of systemic insulin resistance, which is another important risk factor for NAFLD. Diet composition and in particular simple carbohydrate intake (especially high fructose intake) may promote the development of NAFLD, whereas non-digestible carbohydrates (dietary fiber), by affecting gut microbiota, may favour the integrity of gut wall and reduce inflammation, opposing this process. Saturated fat intake may also promote NAFLD development, whereas unsaturated fat intake has some beneficial effects. Protein intake does not seem to affect the development of NAFLD, but further investigation is needed. In conclusion, lifestyle modifications to induce weight loss, through diet and physical activity, remain the mainstay of treatment for paediatric NAFLD. The use of dietary supplements, such as omega-3 fatty acids and probiotics, needs further study before recommendation.

Pediatric Metabolic and Bariatric Surgery

Childhood obesity can lead to comorbidities that cause significant decrease in health-related quality of life and early mortality. Recognition of obesity as a disease of polygenic etiology can help deter implicit bias. Current guidelines for treating severe obesity in children recommend referral to a multidisciplinary treatment center that offers metabolic and bariatric surgery at any age when a child develops a body mass index that is greater than 120% of the 95th percentile. Obesity medications and lifestyle counseling about diet and exercise are not adequate treatment for severe childhood obesity. Early referral can significantly improve quality and quantity of life.

Incidence of cirrhosis in young birth cohorts in Canada from 1997 to 2016: a retrospective population-based study

BACKGROUND

Recent data show that the prevalence of chronic liver disease and cirrhosis is increasing in adolescents and young adults in the USA. We aimed to describe the epidemiology of cirrhosis using an age-period-cohort approach to define birth-cohort effects on the incidence of cirrhosis in Ontario, Canada.

METHODS

We did a retrospective population-based cohort study in Ontario, Canada, using linked administrative health data from the databases of ICES, formerly the Institute for Clinical Evaluative Sciences. Patients aged at least 18 years with cirrhosis were identified by use of a validated case definition (defined as at least one inpatient or outpatient visit with a diagnosis of cirrhosis or oesophageal varices without bleeding). We calculated annual standardised incidence and prevalence in the general population. We used an age-period-cohort approach to assess the independent association between birth cohort and incidence of cirrhosis in men and women.

FINDINGS

Between Jan 1, 1997, and Dec 31, 2016, 165 979 individuals with cirrhosis were identified. The age-standardised incidence increased over the study (from 70·6 per 100 000 person-years in 1997 to 89·6 per 100 000 person-years in 2016) as did the prevalence (from 0·42% in 1997 to 0·84% in 2016). Using age-period-cohort modelling and the median birth year as the reference, the incidence of cirrhosis was higher in participants born in 1980 (incidence rate ratio 1·55, 95% CI 1·50-1·59, p<0·0001); and in participants born in 1990 (2·16, 95% CI 2·06-2·27, p<0·0001) compared with a person of the same age born in 1951. The increase in incidence of cirrhosis was greater in women than in men (eg, women born in 1990: 2·60, 95% CI 2·41-2·79; men born in 1990: 1·98, 1·85-2·12).

INTERPRETATION

The incidence of cirrhosis has increased over the past two decades, and more so in younger birth cohorts and in women. Future studies to define the cause and natural history of cirrhosis in these groups are essential to develop strategies that could reverse these trends for future generations.

FUNDING

Southeastern Ontario Academic Medical Association New Clinician Scientist Award; American Association for the Study of Liver Disease (AASLD) Foundation Clinical, Translational and Outcomes Research Award in Liver Disease (JAF).

ASMBS pediatric metabolic and bariatric surgery guidelines, 2018

The American Society for Metabolic and Bariatric Surgery Pediatric Committee updated their evidence-based guidelines published in 2012, performing a comprehensive literature search (2009-2017) with 1387 articles and other supporting evidence through February 2018. The significant increase in data supporting the use of metabolic and bariatric surgery (MBS) in adolescents since 2012 strengthens these guidelines from prior reports. Obesity is recognized as a disease; treatment of severe obesity requires a life-long multidisciplinary approach with combinations of lifestyle changes, nutrition, medications, and MBS. We recommend using modern definitions of severe obesity in children with the Centers for Disease Control and Prevention age- and sex-matched growth charts defining class II obesity as 120% of the 95th percentile and class III obesity as 140% of the 95th percentile. Adolescents with class II obesity and a co-morbidity (listed in the guidelines), or with class III obesity should be considered for MBS. Adolescents with cognitive disabilities, a history of mental illness or eating disorders that are treated, immature bone growth, or low Tanner stage should not be denied treatment. MBS is safe and effective in adolescents; given the higher risk of adult obesity that develops in childhood, MBS should not be withheld from adolescents when severe co-morbidities, such as depressed health-related quality of life score, type 2 diabetes, obstructive sleep apnea, and nonalcoholic steatohepatitis exist. Early intervention can reduce the risk of persistent obesity as well as end organ damage from long standing co-morbidities.

Bisphenol a increases risk for presumed non-alcoholic fatty liver disease in Hispanic adolescents in NHANES 2003-2010

BACKGROUND

Bisphenol-A (BPA) is a ubiquitous chemical and recognized endocrine disruptor associated with obesity and related disorders. We explored the association between BPA levels and suspected non-alcoholic fatty liver disease (NAFLD).

METHODS

Unweighted analyses were used to study the relationship between urinary BPA levels and suspected NAFLD (alanine aminotransferase (ALT). > 30 U/L, body mass index (BMI) Z-score > 1.064 and evidence of insulin resistance) using National Health and Nutrition Examination Survey (NHANES) data (2003-2010) on 12-19 year olds. Unweighted and weighted analyses were used to evaluate the risk with only elevated ALT.

RESULTS

We included 944 adolescents with urinary BPA and fasting laboratory tests from a total of 7168 adolescents. Risk of suspected NAFLD was increased in the second quartile of BPA levels (1.4-2.7 ng/mL) when compared to the first (< 1.4 ng/mL) (Odds Ratio (OR) 4.23, 95% Confidence Interval (CI) 1.44-12.41). The ORs for the third and second quartiles were positive but did not reach statistical significance. The association was stronger in Hispanics (n = 344) with BPA levels in the second (OR 6.12, 95% C.I. 1.62-23.15) quartile and when limiting the analyses to overweight/obese adolescents (n = 332), in the second (OR 5.56, 95% C.I. 1.28-24.06) and fourth BPA quartiles (OR 6.85, 95% C.I. 1.02-46.22) compared to the first quartile. BPA levels were not associated with ALT elevation.

CONCLUSIONS

The risk of suspected NAFLD is increased in participants in higher quartiles of BPA exposure, particularly in those of Hispanic ethnicity. Further studies are required to fully understand the potential role of BPA in non-alcoholic fatty liver disease.